Replacing insulin through stem cell-derived pancreatic cells under the skin

By NEVAGiles23

LA JOLLA, Calif., March 25, 2014 Sanford-Burnham Medical Research Institute (Sanford-Burnham) and UC San Diego School of Medicine scientists have shown that by encapsulating immature pancreatic cells derived from human embryonic stem cells (hESC), and implanting them under the skin in animal models of diabetes, sufficient insulin is produced to maintain glucose levels without unwanted potential trade-offs of the technology. The research suggests that encapsulated hESC-derived insulin-producing cells hold great promise as an effective and safe cell-replacement therapy for insulin-dependent diabetes.

“Our study critically evaluates some of the potential pitfalls of using stem cells to treat insulin-dependent diabetes,” said Pamela Itkin-Ansari, Ph.D., adjunct assistant professor in the Development, Aging, and Regenerative Program at Sanford-Burnham, with a joint appointment at UC San Diego.

“We have shown that encapsulated hESC-derived pancreatic cells are able to produce insulin in response to elevated glucose without an increase in the mass or their escape from the capsule. These results are important because it means that the encapsulated cells are both fully functional and retrievable,” said Itkin-Ansari.

In the study, published online in Stem Cell Research, Itkin-Ansari and her team used bioluminescent imaging to see if encapsulated cells stay in the capsule after implantation.

Previous attempts to replace insulin-producing cells, called beta cells, have met with significant challenges. For example, researchers have tried treating diabetics with mature beta cells, but because mature cells are fragile and scarce, the method is fraught with problems. Moreover, since the cells come from organ donors, they may be recognized as foreign by the recipient’s immune systemrequiring patients to take immunosuppressive drugs to prevent their immune system from attacking the donor’s cells, ultimately leaving patients vulnerable to infections, tumors, and other adverse events.

Encapsulation technology was developed to protect donor cells from exposure to the immune systemand has proven extremely successful in preclinical studies.

Itkin-Ansari and her research team previously made an important contribution to the encapsulation approach by showing that pancreatic islet progenitor cells are an optimal cell type for encapsulation. They found that progenitor cells were more robust than mature beta cells to encapsulate, and while encapsulated, they matured into insulin-producing cells, which secreted insulin only when needed.